The invention provides a motor drive and power return two-way power source of an electric automobile, and the two-way power source comprises an energy conversion direct current part and a positive motor drive and reverse motor electric energy recovery part, wherein the energy conversion direct current part comprises a two-way DC (direct current) / DC converter, a two-way DC / DC convertor digital control system, a positive inversing and reverse rectifier circuit, a motor drive digital control system, a two-way DC / DC circuit driving and protecting circuit, an inverter circuit driving and protecting circuit, a battery voltage detecting circuit, a battery current detecting circuit, a bus voltage detecting circuit and a motor current detecting circuit. A battery is connected with the two-way DC / DC convertor, so that the bus voltage of a motor driving circuit is adjusted to be a stable value, and the driving circuit drives a permanent magnet synchronous motor to run so as to drive the automobile; and the motor is in an electricity generation status when the automobile is braked, the motor driving circuit transmits the energy to a bus, and a microcontroller detects a brake signal and drives the two-way DC / DC convertor to feed the energy back to the battery. Furthermore, the characteristic and efficiency of the electromagnetic compatibility (EMC) of the power source can be improved.